1. Field of the Invention
The present invention relates generally to the field of telecommunications systems, and, more particularly, the present invention is directed to methods and apparatus for transmitting facsimile-encoded information between multimedia-capable communication terminal equipment.
2. Description of the Related Art
In the field of telecommunications, the transmission of data, video and audio signals is accomplished according to communications protocols such as, ITU-T H.223 or, alternatively, H.245 (the November 1995 version is referenced). In particular, the terminal equipment of telefax group 3 connectable to a communication network via analog interfaces are used mainly for the transmission of digital still pictures. The still pictures to be communicated over the telecommunication networks are comprised of a large number of minute black and white mosaic squares of the same shape and size (called pixels). The original still pictures are either scanned by a scanner and resolved into black or white pixels or are generated by a computer as the result of a document/drawing production. First, they are compressed in order to reduce the necessary amount of information to be transmitted. Then they are divided into information blocks and communicated block-by-block via the telecommunication network. In the receiving telefax terminal equipment, the received information is decompressed and decoded into the original black and white pixels. Thus, an image that looks like the original is compiled (and therefore represents a "facsimile" thereof). The received image is usually printed out on paper by the receiving terminal equipment or, in some cases, is presented on a display picture screen or stored on local digital storage devices such as, for example, a magnetic disk.
The method employed by terminal equipment of telefax group 3 has been standardized according to the International Telecommunication Union (ITU) in the corresponding ITU-T recommendations for group 3 (ITU-T T.4, ITU-T T.6, ITU-T T.30) (latest revision 1995 to date). A facsimile group 3 device is usually a "monomedia" communication terminal equipment, i.e. it can normally only transmit one specific type of information (namely, a facsimile pixel image).
In contrast, multimedia-capable communication terminal equipment are capable of simultaneously transmitting two types of information such as, for example, a facsimile pixel image accompanied with voice.